Twin Research and Human Genetics

Articles

A Web-Based Study of Personality, Psychopathology and Substance Use in Twin, Other Relative and Relationship Pairs

Kenneth S. Kendlera1 c1, John Myersa2, Jeff Pottera3 and Jill Opaleskya4

a1 Virginia Institute of Psychiatric and Behavioral Genetics, Virginia Commonwealth University School of Medicine, Richmond, United States of America; Department of Psychiatry, Virginia Commonwealth University School of Medicine, Richmond, United States of America; Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, United States of America. kendler@vcu.edu

a2 Virginia Institute of Psychiatric and Behavioral Genetics, Virginia Commonwealth University School of Medicine, Richmond, United States of America; Department of Psychiatry, Virginia Commonwealth University School of Medicine, Richmond, United States of America.

a3 Atof Inc, Cambridge, United States of America.

a4 Virginia Institute of Psychiatric and Behavioral Genetics, Virginia Commonwealth University School of Medicine, Richmond, United States of America; Department of Psychiatry, Virginia Commonwealth University School of Medicine, Richmond, United States of America.

Abstract

Web-based studies have become increasingly common in the social sciences, but have been rare in genetic epidemiology in general and twin studies in particular. We here review the methods, validity checks and preliminary correlational data from an on-line questionnaire collected from 2005–2008. During this time period, 44,112 individuals completed the questionnaire. This sample was 65.3% female, 85.4% 18 years or older, 72.0% Caucasian and had a mean educational level of 12.2 years. The sample included 609 twin, 333 sibling and 201 parent-offspring pairs as well as 342 dating partners, 313 ‘significant other’ pairs, 327 spouses and 2,316 friend pairs. A range of checks suggested low levels of invalid data. Correlations for personality, substance use and misuse, lifetime major depression, social attitudes, educational status, and height and weight were broadly similar to those obtained previously using conventional assessment methods. Web-based studies are a relatively easy and inexpensive way to ascertain large numbers of individuals, although obtaining twin pairs is more difficult, and female and monozygotic pairs are overrepresented. The sample is diverse and pair resemblance is generally similar to that obtained using interviews or mailed questionnaires.

(Received December 06 2008)

(Accepted February 02 2009)

Keywords

  • Twins;
  • World Wide Web;
  • personality;
  • drug use

Correspondence:

c1 Address for correspondence: Kenneth Kendler, MD, Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University Medical School, Box 980126, 800 E. Leigh Street, Room 1–123, Richmond, VA 23298-012, United States of America.

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